Interlaboratory standardization of glycated hemoglobin determinations.

As the clinical utility of glycated hemoglobin (gHb) measurement increases, so does the need for standardization of values between different methods and different laboratories. Using three different methods, we examined the feasibility of interlaboratory standardization of gHb measurement. A liquid-chromatographic (HPLC) system from our research laboratory was designated the reference method. For gHb standards we used erythrocyte hemolysates prepared from blood samples from nondiabetic and diabetic subjects. Values assigned to each standard were based on the mean of multiple gHb determinations by the HPLC method. A clinical laboratory routinely prepared hemolysates and assayed gHb by commercially available ion-exchange ("mini column") and affinity chromatographic methods. For each assay a standard curve was constructed and gHb values were derived from these curves. Samples analyzed in the clinical laboratory were also analyzed in the research laboratory and the curve-derived values were compared with the HPLC-measured values, to determine the accuracy of our interlaboratory standardization procedure. Correlations were excellent (r = 0.99). The lack of significant differences between calculated and HPLC-measured values indicates that interlaboratory standardization is feasible.

Hyphal forms of Histoplasma capsulatum. A common manifestation of intravascular infections.

The usual tissue form of Histoplasma capsulatum is a small intracellular yeast, though extracellular organisms of unusually large size have also been described. The production of hyphae in tissue has been regarded as rare and we believe not generally appreciated. We report a case of probable Histoplasma endocarditis from which an embolus demonstrated abundant mycelial forms on histologic examination. Of previously reported cases of H capsulatum endocarditis with detailed pathologic description, nine of 27 cases are found to demonstrate hyphal forms. Hyphal structures should be considered a common morphologic variant of H capsulatum in intravascular lesions.

Objective response in amyloidosis treated with intermittent chemotherapy.

A 37-year-old woman with amyloidosis derived from light chain immunoglobulin had hepatosplenomegaly, elevated serum alkaline phosphatase values, and progressively destructive bony lesions. A 44-month intermittent course of chemotherapy with melphalan and prednisone resulted in regression, confirming the occasional efficacy of cytotoxic chemotherapy in this disease.

Sjögren's syndrome in MRL/l and MRL/n mice.

Six autoimmune murine models (MRL/l, MRL/n, NZB, NZB/NZW, PN, C57BL/6J-lpr/lpr) were compared with normal control C57BL/6J and DBA/2 mice to determine if spontaneous autoimmune disease was associated with evidence of Sjögren's syndrome. Schirmer tests documented dry eyes in NZB/NZW and PN mice; other autoimmune strains and controls had normal tear formation. All autoimmune mice had conjunctivitis, but this abnormality was most severe in the PN strain. Ninety-eight percent of MRL/l and MRL/n mice had mononuclear cell infiltrates in lacrimal glands, and salivary glands were involved to a lesser degree. New Zealand mice and PN mice had smaller gland lesions. The extensive gland destruction in MRL/l and MRL/n mice suggested that these substrains merit further studies as animal models of Sjögren's syndrome.

Cardiovascular manifestations of mixed connective tissue disease in adults.

To assess the nature and distribution of cardiovascular abnormalities associated with mixed connective tissue disease, we studied 38 patients with overlapping clinical manifestations of systemic lupus erythematosus, progressive systemic sclerosis and polymyositis, and circulating antibodies to nuclear ribonucleoprotein. The protocol included taking a medical history and a physical echocardiogram, and pulmonary function tests. Cardiac catheterization was performed on 17 patients. Postmortem examination was performed on four of the five patients who died during follow-up. Acute pericarditis and/or pericardial effusion was detected in 11 patients (29%) and mitral valve prolapse was identified in 10 patients (26%). Marked intimal hyperplasia of coronary arteries was observed in all four hearts that were autopsied and perivascular and myocardial leukocytic aggregates were present in two hearts. Pulmonary vascular resistance was elevated in 11 of the 17 patients who underwent cardiac catheterization. In summary, cardiovascular abnormalities associated with mixed connective tissue disease include acute pericarditis and/or effusion, mitral valve prolapse, intimal hyperplasia of coronary arteries, perivascular and myocardial leukocytic infiltrates, and pulmonary hypertension.

Band keratopathy in MRL/l and MRL/n mice.

To define ocular abnormalities in mice with autoimmune disease, we performed biomicroscopic examinations and examined ocular tissue in MRL/l, MRL/n, NZB, NZB/NZW, and Palmerston North mice. Results were compared with MRL/Mp--lpr/lpr, C57BL/6J--lpr/lpr, and normal control strains. Eighty-seven percent of MRL/l and MRL/n mice had typical band keratopathy; this was confirmed by histologic examination. Posterior uveitis was found in 35% of adult MRL/l mice. MRL substrains are potentially important models of ocular disease.

Rat bladder irrigation with PVP-I2.

Despite technical advances, Foley catheter associated urinary tract infections continue to be the leading cause of nosocomial infections. PVP-I2 has been shown to be nonirritating to abraded tissue and we have shown that dilute solutions are bactericidal for organisms causing Foley catheter associated urinary tract infections. The purpose of this study was to ascertain the toxicity of PVP-I2 on the catheterized rat bladder and to measure the systemic absorption of I2. Bladder catheters were surgically placed into each of 3 groups of rats: group 1, catheters only; group 2, irrigation with PBS q.8h; and group 3, irrigation with a 1:3 dilution of a 10 per cent PVP-1 per cent I2 solution q-8h. One-half of each group was sacrificed at 1 and 2 weeks respectively. Photographs of mounted bladders and histologic sections were then graded by 3 independent observers. Blood for protein bound iodine (PBI), T3 and T4 levels was obtained before the study and at sacrifice. No difference in ulcerations, erythema or inflammation was noted. PBI was higher in group 3 rats at conclusion than group 1 and 2 (6.88 mg./dl. versus 3.42 mg./dl.) (p less than 0.05). There was no difference in T3 or T4 levels. In this study, PVP-I2 was no more toxic to the bladder than catheterization alone or irrigation with PBS.

Variations in the levels of estrogen receptors in prolactin producing pituitary tumor cells.

The binding of [3H]-17 beta-estradiol in cells and cytoplasmic fractions of three different prolactin producing pituitary tumor lines was compared and found to vary widely. The concentration of estrogen receptors of the MtTW10 rat tumor line was high in early passages, but receptor levels decreased with subsequent passages in animals. Over a period of 12 months, the estrogen binding capacity in low speed supernatant fractions of cell homogenates decreased from 61.5 fmol [3H]-17 beta-estradiol per mg protein to less than 10 fmol [3H]-17 beta-estradiol per mg protein. A similar decrease in receptor concentration was found in MtTW10 cells which were adapted to in vitro culture. The concentration of receptor in low speed supernatant fractions of cultured GH3 rat tumor cells remained between 60 and 80 fmol [3H]-17 beta-estradiol per mg protein throughout the entire period of experimentation. In contrast, no high affinity receptors could be detected in similar fractions of the human pituitary cell line, 18-54, when cultured either in the presence or absence of serum. The Kd for the estradiol:receptor complex was determined to be 1.0 x 10(-10) M for receptors from MtTW10 cells and remained constant as the concentration of receptors declined. The receptors in both MtTW10 and GH3 cells were found to exist as 8s molecular species which are converted to 4s species by a temperature dependent process. The binding of estrogen to 8s and 4s receptors at 4 degrees C was shown to occur in the presence of 3 mg/ml of digitonin.

Malabsorption and gastric hyperacidity in systemic mastocytosis. Results of cimetidine therapy.

Visceral infiltration by mast cells (systemic mastocytosis) is an unusual manifestation of cutaneous mastocytosis. Symptomatic gastrointestinal disease occurs in approximately one-fourth of patients having systemic mastocytosis. An unusual gastrointestinal complication is malabsorption, described in sporadic case reports. A patient with gastric acid hypersecretion and malabsorption is described. Treatment using the histamine H2 antagonist, cimetidine, ameliorated the patient's gastrointestinal symptoms; however, the malabsorption was not resolved.

The use of fluorescent and special staining techniques in the aspiration of nocardiosis and actinomycosis.

This report outlines the techniques and illustrates the utility of special stains and fluorescent microscopy when applied to aspiration cytology material. This procedure allowed quick and accurate diagnosis of opportunistic infectious organisms, specifically nocardiosis and actinomycosis.